Method of linearizing a sine and cosine signal

Abstract

A rotary position transducer with a cosine and sine attenuating voltage wave output has the substantially linear portions segmented and pieced together from a predetermined set of conditions to form a continuously linearly varying voltage output.

What is claimed is:  
     
       1. A method of providing an analog electrical signal indicative of the position of a moving object comprising: 
       (a) disposing a magnet for movement with the object;  
       (b) disposing a stationary sensor in a position to be proximate the moving object and electrically exciting the sensor with substantially constant direct current voltage;  
       (c) generating a sine wave voltage signal and a cosine wave signal with the sensor as the object is moved with respect to the sensor;  
       (d) inputting said sine and cosine signal to an amplifier means and multiplexer means and outputting a voltage signal with said sensor according to the following table, where θ represents the instantaneous included angle of rotation of the magnet relative to a reference:  
       
         
           
                 
                 
                 
               
                     
                     
                 
                     
                   Θ 
                   V 
                 
                     
                     
                 
                     
                          0-22.5°  
                     A SIN2Θ + K 1   
                 
                     
                    22.5°-67.5°  
                   −B COS2Θ + K 2   
                 
                     
                    67.5°-112.5° 
                    −A SIN2Θ + K 3   
                 
                     
                   112.5°-157.5° 
                    B COS2Θ + K 4   
                 
                     
                   157.5°-180°   
                     A SIN2Θ + K 1 . 
                 
                     
                     
                 
             
                
                
                
               
               
                
                
                
                
                
                
               
            
           
         
       
     
     
       2. The method defined in  claim 1  wherein said step of disposing a magnet for movement includes disposing a magnet for curvilinear movement with respect to the sensor. 
     
     
       3. The method defined in  claim 1  wherein said step of disposing a magnet for movement includes disposing a magnet for orbital movement about the sensor. 
     
     
       4. The method defined in  claim 1  wherein said step of disposing a magnet for movement includes rotating the magnet with respect to the sensor about an axis passing through the magnet. 
     
     
       5. A method of providing an analog electrical signal indicative of the position of a moving object comprising: 
       (a) disposing a magnet for movement with the object;  
       (b) disposing a stationary sensor in a position to be proximate the moving object and electrically exciting the sensor with a substantially constant direct current voltage;  
       (c) generating a sine wave voltage signal and a cosine wave voltage signal with the sensor as the object is moved with respect to the sensor;  
       (d) inputting said sine and cosine voltage signals to an amplifier means and multiplexer means and outputting a voltage signal according to the following table:  
       
         
           
                 
                 
                 
                 
                 
                 
               
                     
                 
                   V = 
                   S 3   
                   S 2   
                   S 1   
                   S 0   
                     
                 
                     
                 
                     
                 
                 
                 
                 
                 
                 
                 
               
                     A SIN2Θ + K 1    
                   1 
                   — 
                   1 
                   1 
                   where: S 3  = COS2Θ =+ 
                 
                     
                     
                     
                     
                     
                   (or greater than a chosen 
                 
                     
                     
                     
                     
                     
                   reference) 
                 
                   −B COS2Θ + K 2   
                   — 
                   1 
                   0 
                   1 
                   where: S 2  = SIN2Θ =+ 
                 
                     
                     
                     
                     
                     
                   (or greater than a chosen 
                 
                     
                     
                     
                     
                     
                   reference) 
                 
                    −A SIN2Θ + K 3    
                   0 
                   — 
                   0 
                   0 
                   where: S 1  = COS2Θ > SIN2Θ 
                 
                    B COS2Θ + K 4   
                   — 
                   0 
                   1 
                   0 
                   where: S 0  = COS2Θ > −SIN2Θ. 
                 
                     
                 
             
                
                
                
               
               
                
               
            
             
                
                
                
                
                
                
                
                
                
               
            
           
         
       
     
     
       6. A method of providing an analog electrical signal indicative of the position of a moving object comprising: 
       (a) disposing a magnet for movement with the object;  
       (b) disposing a stationary sensor in a position to be proximate the moving object and electrically exciting the sensor with substantially constant direct current voltage;  
       (c) generating a sine wave voltage signal and a cosine wave signal with the sensor as the object is moved with respect to the sensor;  
       (d) inputting said sine and cosine signal to an amplifier means and a comparator means, and outputting a voltage signal with the sensors according to the following table, where θ represents the instantaneous included angle of rotation of the magnet relative to a reference:  
       
         
           
                 
                 
                 
               
                     
                 
                   Θ 
                   Condition 
                   V 
                 
                     
                 
                   22.5° to 67.5°  
                   COS2Θ ≧ −SIN2Θ 
                   −B COS2Θ + K 6   
                 
                   67.5° to 112.5° 
                   COS2Θ ≦ −SIN2Θ 
                   −A SIN2Θ + K 5.   
                 
                     
                 
             
                
                
                
               
               
                
                
                
               
            
           
         
       
     
     
       7. The method defined in  claim 6 , wherein the step of inputting the sine and cosine signal to a comparator means includes inputting the output of the said comparator means to one side of a switch and moving said switch. 
     
     
       8. The method defined in  claim 7 , wherein the step of changing the state of said switch includes moving said switch in response to whether the cosine signal is greater than or less than the sine signal.